This envelope originated from the Paris office at Rue de Clery on October 25, 1870, (seventh collection) and was prepaid 20 centimes for the French internal letter rate to Boulogne-sur-Mer, “Par Ballon Monté.” Based on the date and time of collection plus the arrival datestamp of November 2, 1870, it is likely that this letter was carried out of Paris by the balloon Vauban.

The Vauban carried 290 kilograms of mail. The flight occurred in stormy weather, causing the balloon to soar to dizzying heights and then fall abruptly to earth. The balloon descended into enemy-occupied territory, and the dispatches were forwarded to Fresnes and Bar-le-Duc, where the letters entered the French mail system.